In the human body, various organs contain fluids both in liquids and gaseous forms within tissue layers or cavities formed by tissue. These liquids may or may not be under pressure. The tissue walls around these cavities are normally designed to confine these liquids to specific areas of the body. Blood as in the heart and vasculature in order to preserve its volume and transport oxygen to tissue, gastric and intestinal fluids as in the stomach and intestines in order to transport remains of digestion out of the body after nutrients are absorbed, urine in the bladder in order to expel liquid waste from the body, fluid within the eye to maintain its shape and passage of light, are examples of such tissue fluid confining systems. During medical procedures within these cavities it is of extreme importance to control the fluid within. The most common example is cardiopulmonary bypass during open hearts surgery, although, in all procedures associated with the system above emphasis is placed on control of the fluid within the organ. For this control, sometimes extra space is required to conduct these interventions; therefore, highly invasive procedures may be required for surgery within these cavities, especially while maintaining organ function. The most complex example of these being beating heart surgery. For less invasive procedures, especially those within the vascular system, access ports or conduits which allow for fluid communication, control and tissue closure within the organ being repaired are therefore required.
The various conduit and port devices and systems described herein may be utilized as an accompaniment with any number of surgical procedures to gain access through a variety of possible tissues. For example, the conduit devices and systems may be utilized to provide fluid access across a tissue wall, such as, but not limited to, upon establishing an AAC, upon establishing a port for inter-ventricular repairs (e.g., valve repair, valve replacement, or ablation procedures, etc.), upon establishing valved and/or open conduits (including bypass conduits) to augment native blood vessels in order to treat a variety of vascular conditions (e.g., aortic valvular disease, congestive heart failure, left ventricle outflow tract obstructions (“LVOTO”), peripheral arterial obstructions, small vessel obstructions, etc.), upon providing a conduit across a urinary bladder wall, upon providing a conduit across a gall bladder wall, upon providing a conduit into a thoracic cavity, upon providing a conduit into an abdominal cavity, upon providing a conduit into a cecal cavity, upon providing access into the cornea or eye walls, or upon providing access across or into any other tissue wall structures. Accordingly, the conduit devices and systems described herein may be utilized with any of the aforementioned procedures and/or to gain access through any of the aforementioned tissue walls.
Because of the importance of heart function and the complexities associated to this pressurized system, some of the most complex procedures associated with bodily fluids are performed on this organ. Several of these procedures would benefit from a conduit or port which can maintain a fluid tight seal with tissue surfaces.
Heart valve replacement is the most common open heart cardiovascular surgery procedure, currently most heart valve repair or replacement surgeries are conducted on a heart at rest under cardiopulmonary bypass through a large median sternotomy. This surgery is highly invasive, and therefore, the population that may survive such a procedure is limited to those who are strong surgical candidates. In recent years valves for minimally invasive deployment through the femoral artery or apex of the heart have been developed. These valves may be used in patients that would under other conditions be deemed non-candidates. The use of these valves may also in the future reduce complications associated with cardiopulmonary bypass and large incisions in surgical candidates. For those procedures through the apex of the heart it has been shown that bleeding complications are directly associated with 50% increased mortality, therefore, and access conduit or port which would reduce bleeding complications, decrease incision size and simplify closure would be of great benefit.
Another procedure that would benefit from a fluid tight conduit or port into the heart would be the construction of an alternative conduit between the left ventricle and the aorta (an apicoaortic conduit, or AAC). This procedure creates a double-outlet left ventricle (LV) to treat a variety of complex congenital LV outflow obstruction (fibrous tunnel obstruction, aortic annular hypoplasia, tubular hypoplasia of the ascending aorta, and patients with diffuse septal thickening, severe LV hypertrophy and a small LV cavity) as well as adult-onset aortic stenosis in patients with complicating preoperative conditions (previous failed annular augmentation procedures, previous infection, previous CABG with patent anterior internal mammary artery grafts, and a porcelain ascending aorta). However, the AAC insertion procedure has been poorly accepted, with or without cardiopulmonary bypass, has not been as technically straightforward as direct aortic valve replacement. Nonetheless, several studies have demonstrated that AAC insertion successfully lessens the LV-aortic pressure gradient, preserves or improves ventricular function and maintains normally distributed blood flow through the systemic and coronary circulation.
While there have been several techniques described, the most commonly employed method is the lateral thoracotomy approach with placement of the AAC to the descending aorta or a median sternotomy. The current techniques and technology available to perform AAC insertion were originally designed to be performed on-pump; either with an arrested or fibrillating heart, therefore, highly invasive. While off-pump cases have been described, they can be technically difficult due to the shortcomings of presently available conduits and systems for installing such conduits. For example, because existing conduits require the use of sutures to reliably secure the connector in place, it is often difficult for surgeons or other clinicians to insert such sutures reliably in active cardiac and/or vascular tissue.
Some devices and methods have been devised to install an AAC conduit, such as those described generally in U.S. Patent Publication No. 2006/0089707 which is hereby incorporated by reference herein in its entirety. However, these AAC conduit devices and installation systems rely on the use of a flexible flange that is inserted through a pre-defined aperture in the ventricular apex. Thus, such methods require the use of a haemostatic device (such as an occlusion balloon and/or “umbrella” device) to prevent blood loss from the aperture during installation of the AAC conduit. Other apical conduit devices are described in U.S. Pat. No. 7,846,123, which is also hereby incorporated by reference in its entirety.
Accordingly, improved beating heart fluid tight conduits for heart surgery as such described herein, are desirable.